BoundingSphere.h

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/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */
 
#ifndef META_OCEAN_MATH_BOUNDING_SPHERE_H
#define META_OCEAN_MATH_BOUNDING_SPHERE_H
 
#include "ocean/math/Math.h"
#include "ocean/math/BoundingBox.h"
#include "ocean/math/Sphere3.h"
 
namespace Ocean
{
 
/**
 * This class implements a bounding sphere.
 * @ingroup math
 */
class OCEAN_MATH_EXPORT BoundingSphere : public SphereT3<Scalar>
{
    public:
 
        /**
         * Creates an invalid bounding sphere.
         */
        inline BoundingSphere();
 
        /**
         * Creates a new bounding sphere by a center point and a radius.
         * @param center Center of the bounding sphere
         * @param radius Radius of the bounding sphere
         */
        inline BoundingSphere(const Vector3& center, const Scalar radius);
 
        /**
         * Creates a new bounding sphere by a given bounding box.
         * @param boundingBox Bounding box to be converted
         */
        inline explicit BoundingSphere(const BoundingBox& boundingBox);
 
        /**
         * Returns both intersection points between a given ray and this sphere.
         * The intersection points are determined without consideration of the ray direction<br>.
         * @param ray Ray to determine the nearest intersection point for
         * @param position0 Resulting nearest intersection position
         * @param distance0 Resulting nearest intersection distance, regarding to the length of the ray direction
         * @param position1 Resulting farthest intersection position
         * @param distance1 Resulting farthest intersection distance, regarding to the length of the ray direction
         * @return True, if so
         */
        bool intersections(const Line3& ray, Vector3& position0, Scalar& distance0, Vector3& position1, Scalar& distance1) const;
 
        /**
         * Returns both intersection points between a given ray and this sphere.
         * The intersection points are determined without consideration of the ray direction<br>.
         * @param ray Ray to determine the nearest intersection point for
         * @param transformation Transformation of the given world transformation (for the sphere)
         * @param invertedTransformation Inverted transformation of the given world transformation (for the sphere)
         * @param position0 Resulting nearest intersection position
         * @param distance0 Resulting nearest intersection distance, regarding to the length of the ray direction
         * @param position1 Resulting farthest intersection position
         * @param distance1 Resulting farthest intersection distance, regarding to the length of the ray direction
         * @return True, if so
         */
        inline bool intersections(const Line3& ray, const HomogenousMatrix4& transformation, const HomogenousMatrix4& invertedTransformation, Vector3& position0, Scalar& distance0, Vector3& position1, Scalar& distance1) const;
 
        /**
         * Returns both intersection points between a given ray and this sphere.
         * The intersection points are determined without consideration of the ray direction<br>.
         * @param ray Ray to determine the nearest intersection point for
         * @param position0 Resulting nearest intersection position
         * @param distance0 Resulting nearest intersection distance, regarding to the length of the ray direction
         * @param normal0 Resulting nearest intersection normal
         * @param position1 Resulting farthest intersection position
         * @param distance1 Resulting farthest intersection distance, regarding to the length of the ray direction
         * @param normal1 Resulting farthest intersection normal
         * @return True, if so
         */
        inline bool intersections(const Line3& ray, Vector3& position0, Scalar& distance0, Vector3& normal0, Vector3& position1, Scalar& distance1, Vector3& normal1) const;
 
        /**
         * Returns both intersection points between a given ray and this sphere.
         * The intersection points are determined without consideration of the ray direction<br>.
         * @param ray Ray to determine the nearest intersection point for
         * @param transformation Transformation of the given world transformation (for the sphere)
         * @param invertedTransformation Inverted transformation of the given world transformation (for the sphere)
         * @param position0 Resulting nearest intersection position
         * @param distance0 Resulting nearest intersection distance, regarding to the length of the ray direction
         * @param normal0 Resulting nearest intersection normal
         * @param position1 Resulting farthest intersection position
         * @param distance1 Resulting farthest intersection distance, regarding to the length of the ray direction
         * @param normal1 Resulting farthest intersection normal
         * @return True, if so
         */
        inline bool intersections(const Line3& ray, const HomogenousMatrix4& transformation, const HomogenousMatrix4& invertedTransformation, Vector3& position0, Scalar& distance0, Vector3& normal0, Vector3& position1, Scalar& distance1, Vector3& normal1) const;
 
        /**
         * Returns the front intersection point between a given ray and this sphere whenever the distance is positive.
         * The dot product between the ray direction and the intersection normal will be negative.<br>
         * @param ray Ray to determine the intersection point for
         * @param position Resulting intersection position
         * @param distance Resulting intersection distance
         * @return True, if so
         */
        bool positiveFrontIntersection(const Line3& ray, Vector3& position, Scalar& distance) const;
 
        /**
         * Returns the front intersection point between a given ray and this sphere whenever the distance is positive.
         * The dot product between the ray direction and the intersection normal will be negative.<br>
         * @param ray Ray to determine the intersection point for
         * @param position Resulting intersection position
         * @param distance Resulting intersection distance
         * @param normal Resulting intersection normal
         * @return True, if so
         */
        inline bool positiveFrontIntersection(const Line3& ray, Vector3& position, Scalar& distance, Vector3& normal) const;
 
        /**
         * Returns the front intersection point between a given ray and this sphere whenever the distance is positive.
         * The dot product between the ray direction and the intersection normal will be negative.<br>
         * @param ray Ray to determine the intersection point for
         * @param transformation Transformation of the given world transformation (for the sphere)
         * @param invertedTransformation Inverted transformation of the given world transformation (for the sphere)
         * @param position Resulting intersection position
         * @param distance Resulting intersection distance
         * @return True, if so
         */
        inline bool positiveFrontIntersection(const Line3& ray, const HomogenousMatrix4& transformation, const HomogenousMatrix4& invertedTransformation, Vector3& position, Scalar& distance) const;
 
        /**
         * Returns the front intersection point between a given ray and this sphere whenever the distance is positive.
         * The dot product between the ray direction and the intersection normal will be negative.<br>
         * @param ray Ray to determine the intersection point for
         * @param transformation Transformation of the given world transformation (for the sphere)
         * @param invertedTransformation Inverted transformation of the given world transformation (for the sphere)
         * @param position Resulting intersection position
         * @param distance Resulting intersection distance
         * @param normal Resulting intersection normal
         * @return True, if so
         */
        inline bool positiveFrontIntersection(const Line3& ray, const HomogenousMatrix4& transformation, const HomogenousMatrix4& invertedTransformation, Vector3& position, Scalar& distance, Vector3& normal) const;
 
        /**
         * Returns the back intersection point between a given ray and this sphere whenever the distance is positive.
         * The dot product between the ray direction and the intersection normal will be positive.<br>
         * @param ray Ray to determine the intersection point for
         * @param position Resulting intersection position
         * @param distance Resulting intersection distance
         * @return True, if so
         */
        bool positiveBackIntersection(const Line3& ray, Vector3& position, Scalar& distance) const;
 
        /**
         * Returns the back intersection point between a given ray and this sphere whenever the distance is positive.
         * The dot product between the ray direction and the intersection normal will be positive.<br>
         * @param ray Ray to determine the intersection point for
         * @param position Resulting intersection position
         * @param distance Resulting intersection distance
         * @param normal Resulting intersection normal
         * @return True, if so
         */
        inline bool positiveBackIntersection(const Line3& ray, Vector3& position, Scalar& distance, Vector3& normal) const;
 
        /**
         * Returns the back intersection point between a given ray and this sphere whenever the distance is positive.
         * The dot product between the ray direction and the intersection normal will be positive.<br>
         * @param ray Ray to determine the intersection point for
         * @param transformation Transformation of the given world transformation (for the sphere)
         * @param invertedTransformation Inverted transformation of the given world transformation (for the sphere)
         * @param position Resulting intersection position
         * @param distance Resulting intersection distance
         * @return True, if so
         */
        inline bool positiveBackIntersection(const Line3& ray, const HomogenousMatrix4& transformation, const HomogenousMatrix4& invertedTransformation, Vector3& position, Scalar& distance) const;
 
        /**
         * Returns the back intersection point between a given ray and this sphere whenever the distance is positive.
         * The dot product between the ray direction and the intersection normal will be positive.<br>
         * @param ray Ray to determine the intersection point for
         * @param transformation Transformation of the given world transformation (for the sphere)
         * @param invertedTransformation Inverted transformation of the given world transformation (for the sphere)
         * @param position Resulting intersection position
         * @param distance Resulting intersection distance
         * @param normal Resulting intersection normal
         * @return True, if so
         */
        inline bool positiveBackIntersection(const Line3& ray, const HomogenousMatrix4& transformation, const HomogenousMatrix4& invertedTransformation, Vector3& position, Scalar& distance, Vector3& normal) const;
 
    private:
 
        /// Inverse of the sphere radius.
        Scalar inverseRadius_;
};
 
inline BoundingSphere::BoundingSphere() :
    Sphere3(),
    inverseRadius_(0)
{
    // nothing to do here
}
 
inline BoundingSphere::BoundingSphere(const Vector3& center, const Scalar radius) :
    Sphere3(center, radius),
    inverseRadius_((radius > 0) ? (Scalar(1) / radius) : Scalar(0))
{
    // nothing to do here
}
 
inline BoundingSphere::BoundingSphere(const BoundingBox& boundingBox) :
    Sphere3(boundingBox)
{
    inverseRadius_ = (radius_ > 0) ? (Scalar(1) / radius_) : Scalar(0);
}
 
inline bool BoundingSphere::intersections(const Line3& ray, const HomogenousMatrix4& transformation, const HomogenousMatrix4& invertedTransformation, Vector3& position0, Scalar& distance0, Vector3& position1, Scalar& distance1) const
{
    ocean_assert(isValid());
    ocean_assert(transformation.isValid());
    ocean_assert(invertedTransformation.isValid());
    ocean_assert(ray.isValid());
 
    if (intersections(Line3(invertedTransformation * ray.point(), invertedTransformation.rotationMatrix(ray.direction())), position0, distance0, position1, distance1))
    {
        position0 = transformation * position0;
        position1 = transformation * position1;
        return true;
    }
 
    return false;
}
 
inline bool BoundingSphere::intersections(const Line3& ray, Vector3& position0, Scalar& distance0, Vector3& normal0, Vector3& position1, Scalar& distance1, Vector3& normal1) const
{
    ocean_assert(isValid());
    ocean_assert(ray.isValid());
 
    if (intersections(ray, position0, distance0, position1, distance1))
    {
        normal0 = (position0 - center_) * inverseRadius_;
        normal1 = (position1 - center_) * inverseRadius_;
 
        return true;
    }
 
    return false;
}
 
inline bool BoundingSphere::intersections(const Line3& ray, const HomogenousMatrix4& transformation, const HomogenousMatrix4& invertedTransformation, Vector3& position0, Scalar& distance0, Vector3& normal0, Vector3& position1, Scalar& distance1, Vector3& normal1) const
{
    ocean_assert(isValid());
    ocean_assert(transformation.isValid());
    ocean_assert(invertedTransformation.isValid());
    ocean_assert(ray.isValid());
 
    if (intersections(Line3(invertedTransformation * ray.point(), invertedTransformation.rotationMatrix(ray.direction())), position0, distance0, normal0, position1, distance1, normal1))
    {
        position0 = transformation * position0;
        normal0 = invertedTransformation.transposedRotationMatrix(normal0).normalizedOrZero();
 
        position1 = transformation * position1;
        normal1 = invertedTransformation.transposedRotationMatrix(normal1).normalizedOrZero();
        return true;
    }
 
    return false;
}
 
inline bool BoundingSphere::positiveFrontIntersection(const Line3& ray, Vector3& position, Scalar& distance, Vector3& normal) const
{
    ocean_assert(isValid());
    ocean_assert(ray.isValid());
 
    if (positiveFrontIntersection(ray, position, distance))
    {
        normal = (position - center_) * inverseRadius_;
        ocean_assert(ray.direction() * normal <= 0);
 
        return true;
    }
 
    return false;
}
 
inline bool BoundingSphere::positiveFrontIntersection(const Line3& ray, const HomogenousMatrix4& transformation, const HomogenousMatrix4& invertedTransformation, Vector3& position, Scalar& distance) const
{
    ocean_assert(isValid());
    ocean_assert(transformation.isValid());
    ocean_assert(invertedTransformation.isValid());
    ocean_assert(ray.isValid());
 
    if (positiveFrontIntersection(Line3(invertedTransformation * ray.point(), invertedTransformation.rotationMatrix(ray.direction())), position, distance))
    {
        position = transformation * position;
        return true;
    }
 
    return false;
}
 
inline bool BoundingSphere::positiveFrontIntersection(const Line3& ray, const HomogenousMatrix4& transformation, const HomogenousMatrix4& invertedTransformation, Vector3& position, Scalar& distance, Vector3& normal) const
{
    ocean_assert(isValid());
    ocean_assert(transformation.isValid());
    ocean_assert(invertedTransformation.isValid());
    ocean_assert(ray.isValid());
 
    if (positiveFrontIntersection(Line3(invertedTransformation * ray.point(), invertedTransformation.rotationMatrix(ray.direction())), position, distance, normal))
    {
        position = transformation * position;
        normal = invertedTransformation.transposedRotationMatrix(normal).normalizedOrZero();
        return true;
    }
 
    return false;
}
 
inline bool BoundingSphere::positiveBackIntersection(const Line3& ray, Vector3& position, Scalar& distance, Vector3& normal) const
{
    ocean_assert(isValid());
    ocean_assert(ray.isValid());
 
    if (positiveBackIntersection(ray, position, distance))
    {
        normal = (position - center_) * inverseRadius_;
        ocean_assert(ray.direction() * normal >= 0);
 
        return true;
    }
 
    return false;
}
 
inline bool BoundingSphere::positiveBackIntersection(const Line3& ray, const HomogenousMatrix4& transformation, const HomogenousMatrix4& invertedTransformation, Vector3& position, Scalar& distance) const
{
    ocean_assert(isValid());
    ocean_assert(transformation.isValid());
    ocean_assert(invertedTransformation.isValid());
    ocean_assert(ray.isValid());
 
    if (positiveBackIntersection(Line3(invertedTransformation * ray.point(), invertedTransformation.rotationMatrix(ray.direction())), position, distance))
    {
        position = transformation * position;
        return true;
    }
 
    return false;
}
 
inline bool BoundingSphere::positiveBackIntersection(const Line3& ray, const HomogenousMatrix4& transformation, const HomogenousMatrix4& invertedTransformation, Vector3& position, Scalar& distance, Vector3& normal) const
{
    ocean_assert(isValid());
    ocean_assert(transformation.isValid());
    ocean_assert(invertedTransformation.isValid());
    ocean_assert(ray.isValid());
 
    if (positiveBackIntersection(Line3(invertedTransformation * ray.point(), invertedTransformation.rotationMatrix(ray.direction())), position, distance, normal))
    {
        position = transformation * position;
        normal = invertedTransformation.transposedRotationMatrix(normal).normalizedOrZero();
        return true;
    }
 
    return false;
}
 
}
 
#endif // META_OCEAN_MATH_BOUNDING_SPHERE_H